Brown onion in margarine.,Stir in,flour,,salt, sugar and pepper.,Cook until smooth and,bubbly, stirring constantly. Remove from heat.,______,cups tomato juice or canned tomatoes.,Bring to a boil,	stirring constantly and boil for 1 minute.,Add 2 cups cold whole milk,	all,at once. Heat rapidly,to,serving temperature,,stirring,constantly. Serve at once.